Re: HIGH latch free Wait on moving from RBO to CBO?

There are a number of hidden parameters changed in 9i that affected CBO (as compared to
8i CBO). I suggest contacting Oracle Support before changing any hidden parameters. I
think this is know problem. If possible, test your application with 9.2.0.6. That seems
to a stable version of 9i, so far.

Regards,

Kirti

VIVEK_SHARMA <VIVEK_SHARMA_at_infosys.com> wrote:

> > ISSUE - Getting HIGH Latch Free Wait on the following Latches after moving from RBO to> CBO. ( ALL Objects been analyzed at 100 %). CPU Usage on DB Server has gone up by about> 30 %. NOTE - Application has also been migrated to a Higher release along with the CBO> movement.> > Qs Any init.ora parameters to Tune ?> > Would increasing _shared_pool_reserved_min_alloc to 6140 from the Default of 4400 Help?> > Setting cursorsharing = FORCE/SIMILAR caused "%sys" component of CPU Usage to shoot to> 99 % within minutes of Database startup. Seemed to be hitting some Bug in 9.2.0.5 (64> Bit) on Solaris 9. Has anybody experienced this & is it solved in a 9i Higher Patch ?> Which Patch on 9i is advisable?> > Qs Will Tuning of individual SQLs reduce this wait ?> > Any Other Advice please?> > Top 5 Timed Events> ~~~~~~~~~~~~~~~~~~ % Total> Event Waits Time (s) Ela Time> -------------------------------------------- ------------ ----------- --------> latch free 17,386,965 457,377 63.67> CPU time 121,612 16.93> db file sequential read 142,824,481 72,252 10.06> log file sync 982,290 28,909 4.02> db file scattered read 8,532,496 14,464 2.01> -------------------------------------------------------------> Wait Events for DB: UBIFIN Instance: UBIFIN Snaps: 1515 -1517> > Latch Activity for DB:> Pct Avg Wait Pct> Get Get Slps Time NoWait NoWait> Latch Requests Miss /Miss (s) Requests Miss> ------------------------ -------------- ------ ------ ------ ------------ ------> cache buffers chains 4,141,035,268 0.3 1.2 0 311,630,019 26.7> cache buffers lru chain 3,785,689 6.1 0.2 2300 321,104,446 25.1> library cache 86,823,459 1.3 0.5 31780 56,524 17.4> > > Database Size 1 TB , Number of Concurrent Users = 5000 ,> > Application Hybrid Application - Banking Product , Oracle 9.2.0.5 (64-Bit), Solaris 9,> Number of CPUs on DB Server = 48> > Thanks Folks> > Vivek> > P.S. include my yahoo id (in CC) while replying please if possible> > > **************** CAUTION - Disclaimer *****************> This e-mail contains PRIVILEGED AND CONFIDENTIAL INFORMATION intended solely for the> use of the addressee(s). If you are not the intended recipient, please notify the> sender by e-mail and delete the original message. Further, you are not to copy,> disclose, or distribute this e-mail or its contents to any other person and any such> actions are unlawful. This e-mail may contain viruses. Infosys has taken every> reasonable precaution to minimize this risk, but is not liable for any damage you may> sustain as a result of any virus in this e-mail. You should carry out your own virus> checks before opening the e-mail or attachment. Infosys reserves the right to monitor> and review the content of all messages sent to or from this e-mail address. Messages> sent to or from this e-mail address may be stored on the Infosys e-mail system.> ***INFOSYS******** End of Disclaimer ********INFOSYS***> --> http://www.freelists.org/webpage/oracle-l> > >